Solar panel charge controller

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fortynine

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Having fitted a 10w solar panel and charge controller I find my battery is losing voltage. If however I bypass the charge controller it gains voltage. The charge controller has five LEDs showing load and battery condition so could all this illumination be using more voltage than the solar panel is providing and if so is it possible to disconnect the LEDs?
 
Some of the cheap solar regulators are very inefficient. It is probably one of the on/off regulators. They can turn off for long periods. What regulator is it?

With only a 10w panel you should be able to connect the panel directly, especially in the UK, if your battery bank is a reasonable size.
 
I'm not sure that you'll be producing much energy at all with a 10W solar panel. At 100% efficiency it'll be producing only 0.85A. You probably don't need a controller even on the longest day of the year with sunshine throughout the day. I'm not sure what may be causing your losses but you can certainly bypass the controller what you're on board and using the batteries.
 
Get rid of the controller, all battery manafactures allow for a constant 2% charge at full capacity without any damage. So if you have a a 100w solar panel and a 300ah domestic bank (in the UK) the chances of over charging are very small.

The caveate is in the UK as I have calculated that the panel efficiency will only be 50%
 
A commonly quoted rule of thumb regarding the need, or otherwise, for a regulator is that if the ratio of solar panel power, in watts, to battery capacity, in Ah does not exceed 1 watt per 10 Ah a regulator is not required except that a regulator is generally recommended for panels greater than 10 watts.

This means that if a 10 watt panel is connected to a battery of 100Ah, or greater, a regulator is not needed. If the battery is smaller a regulator is advisable.
 
Thanks for the advice as always. The battery is 75ah so I fitted the regulator to be on the safe side. Unless I can disconnect the LEDs I think I will just charge directly from the panel. Cue wall to wall sunshine for the next 3 months.
 
Even if you are able to disconnect the LED's it's unlikely that it would make much difference. LED's don't use a lot of power.

You haven't said what controller you have but, from what you say, something is wrong if you are losing power by having it connected.

FWIW connecting a 10watt panel direct to a 75ah battery will be fine.
 
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